The invention relates to a method for removing loose coal on wavy surfaces of long, narrow coal cakes that have been compacted by stamping and are used for coking by scraping off the loose coal.
In addition, the invention relates to a device for accomplishing the method.
To compact coal with a high content of volatile constituents, granular coal is filled into molds and compacted there by means of stamping. Stampers are used which have to be disposed spaced apart due to structural constraints and accordingly are not able to work the entire cross-section of the coal cake. Consequently, at the end the surface is not uniformly compacted; wavy regions are formed with loose lying coal on peaks and tamped coal in valleys.
Since the loose coal is swirled around the coke oven by the gas flows during the coking process, causing heavy contamination there, it has to be removed from the coal cake beforehand.
In the case of the aforementioned method known through usage, when the coal cake is displaced into the coke oven, the loose coal is pushed off the coal cake out to the sides by means of a plow-like scraper, which is intended to set up a defined spacing between coal cake and oven ceiling, and falls into chutes installed next to the coal cake. A conveyor transports said coal away to be re-processed. The rest of the loose coal remains on the surface of the coal cake.